Integrated fan out antenna and method of forming the same

ABSTRACT

An integrated fan out (InFO) antenna includes a reflector on a surface of a substrate; and a package. The package includes a redistribution layer (RDL) arranged to form an antenna ground, and a patch antenna over the RDL, wherein the RDL is between the patch antenna and the reflector. The InFO antenna further includes a plurality of connecting elements bonding the package to the reflector. Each connecting element of the plurality of connecting elements is located inside an outer perimeter of the reflector. The InFO antenna is configured to output a signal having a wavelength.

BACKGROUND

An integrated antenna includes an active circuit which generates asignal. The signal is then transferred to passive antenna elementselectrically connected to the active circuit. The passive antennaincludes a reflector on a printed circuit board (PCB) and a patchantenna on a package. The package is bonded to the PCB to space thereflector from the patch antenna. The reflector and patch antennainteract to transmit the signal to external devices.

Some passive antennas include an air cavity in the PCB. The air cavityincludes sidewalls and a bottom surface lined with reflective materialin order to form the reflector. Other passive antennas include areflector on a surface of a PCB and the patch antenna in the packagespaced from the reflector. The package is bonded to the PCB using solderball surrounding the reflector and spaced from a perimeter of thereflector.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1A is a cross-sectional view of an integrated fan out antenna inaccordance with some embodiments.

FIG. 1B is a bottom view of an integrated fan out antenna in accordancewith some embodiments.

FIG. 2A is a cross-sectional view of an integrated fan out antenna arrayin accordance with some embodiments.

FIG. 2B is a perspective view of an integrated fan out antenna array inaccordance with some embodiments.

FIG. 3 is a flowchart of a method of making an integrated fan outantenna in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

FIG. 1A is a cross-sectional view of an integrated fan out (InFO)antenna 100 in accordance with some embodiments. InFO antenna 100includes a substrate 102. A reflector 104 is on a surface of substrate102. Connecting elements 106 are on a surface of reflector 104.Connecting elements 106 are located within a perimeter of reflector 104.Connecting elements 106 electrically connect substrate 102 to a package110. Package 110 includes a redistribution layer (RDL) 112 electricallyconnected to connecting elements 106. RDL 112 is electrically connectedto an active circuit (not shown). RDL 112 forms an antenna ground ofInFO antenna 100. RDL 112 also forms a feed structure of InFO antenna100, which includes a transmission line and a slot line. The feedstructure is a portion of InFO antenna 100 which propagates radio wavesto other components within the InFO antenna. A molding compound 114 isover RDL 112. A patch antenna 116 is over molding compound 114. Patchantenna 116 is above and is substantially centered over reflector 104. Apitch between connecting elements 106 helps to reduce a risk of signalsreflected between patch antenna 116 and reflector 104 from passingbetween adjacent connecting elements.

Substrate 102 supports reflector 104. In some embodiments, substrate 102includes active circuitry. In some embodiments, substrate 102 includespassive circuitry. In some embodiments, substrate 102 is a printedcircuit board (PCB). In some embodiments, substrate 102 is aninterposer.

Reflector 104 is configured to reflect a signal from the active circuitback toward package 110. Reflector 104 is on a surface of substrate 102closest to package 110. In some embodiments, reflector 104 is on asurface of substrate 102 opposite package 110. Reflector 104 includesmetal, metal alloy, or another suitable reflective element. In someembodiments, reflector 104 includes aluminum, copper, tungsten nickel,combinations thereof, or another suitable reflective material.

Reflector 104 has a rectangular shape. In some embodiments, reflector104 is circular, triangular or another suitable shape. Reflector 104 hasan area greater than antenna patch 116. The area of reflector 104 isless than the antenna ground formed by RDL 112. In some embodiments,reflector 104 has dimensions of about 1100 microns (μm)×about 1100 μm.In some embodiments, reflector 104 has dimensions of about 1300 μm×about1300 μm. In some embodiments, reflector 104 has dimensions of about 1500μm×about 1500 μm. In some embodiments, a diameter of reflector 104ranges from about 1100 μm to about 1500 μm. If a dimension of reflector104 is too small, the reflector will not be able to reflect asignificant portion of the signal, in some embodiments. If a dimensionof reflector 104 is too large, an overall size of InFO antenna 100 isincreased without a significant increase in performance.

Connecting elements 106 are used to electrically and mechanicallyconnect package 110 to substrate 102. Connecting elements 106 arelocated directly above reflector 104 inside an outer perimeter of thereflector. Connecting elements 106 are arranged around the periphery ofreflector 104. In some embodiments, connecting elements 106 are solderballs. In some embodiments, connecting elements 106 are copper pillars.In some embodiments, connecting elements 106 include at least one underbump metallurgy (UBM) layer between the connecting elements and package110. In some embodiments, the UBM layer includes a diffusion barrierlayer to reduce material of connecting elements 106 from diffusing intopackage 110. In some embodiments, connecting elements 106 are in directcontact with reflector 104. In some embodiments, connecting elements 106are separated from reflector 104 by a portion of substrate 102. In someembodiments, connecting elements 106 are separated from reflector 104 byat least one UBM layer.

A diameter D of connecting elements 106 is selected to help create acavity between the antenna ground and reflector 104, in someembodiments. In some embodiments, the diameter D of connecting elements106 ranges from about 200 μm to about 350 μm. In some embodiments, thediameter D of connecting elements 106 is about 250 μm. If the diameter Dof connecting elements 106 is too small, the separation between package110 and substrate 102 is not sufficient to establish a cavity forreflecting the signal, in some embodiments. If the diameter D ofconnecting elements D is too large, a risk of bridging between adjacentconnecting elements increases; a size of InFO antenna 100 is increased;an area of reflector 104 occupied by connecting elements becomes toolarge for the reflector to function properly, in some embodiments. Thepitch P (FIG. 1B) between adjacent connecting elements 106 helps toavoid the signal from passing between the adjacent connecting elements.In some embodiments, the pitch P is greater than about 1.5 times thediameter D of connecting elements 106. In some embodiments, the pitch Pranges from about 300 μm to about 550 μm. In some embodiments, the pitchP is about 400 μm. If the pitch P is too small, a risk of bridgingbetween adjacent connecting elements 106 is increased, in someembodiments. If the pitch P is too large, a risk of the signal passingbetween adjacent connecting elements 106 increases, in some embodiments.A number of connective elements 106 in InFO antenna 100 is determined bya size of reflector 104, the diameter D of the connective elements, andthe pitch P between adjacent connective elements. In some embodiments, amaximum number of connective elements 106 are formed directly abovereflector 104. The maximum number of connective elements 106 isdetermined by a minimum spacing between adjacent connective elements 106while avoiding bridging, i.e., short circuiting, between the adjacentconnective elements. In some embodiments, the number of connectiveelements 106 is about 10. If the number of connecting elements 106 istoo small, the risk of the signal passing between adjacent connectingelements increases, in some embodiments. If the number of connectingelements 106 is too large, the risk of bridging between adjacentconnecting elements increases, in some embodiments.

RDL 112 is connected to the active circuit. In addition, RDL 112 is thefeeding structure of InFO antenna 100, as discussed above. RDL 112 isconfigured to convey the signal generated in the active circuit to InFOantenna 100. RDL 112 interacts with reflector 104 and patch antenna 116to help produce the signal for propagation to external circuitry. Insome embodiments, RDL 112 includes copper, aluminum, tungsten,combinations thereof or other suitable conductive elements.

RDL 112 forms the antenna ground having an area greater than reflector104. An outer perimeter of the antenna ground extends laterally beyondthe outer perimeter of reflector 104 in all directions (FIG. 1B). Theantenna ground has a rectangular shape. In some embodiments, the antennaground is circular, triangular or another suitable shape. In someembodiments, the antenna ground has a same shape as reflector 104. Insome embodiments, the antenna ground has a different shape fromreflector 104. In some embodiments, a width Wg of the antenna ground isat least twice a width Wp of patch antenna 116. A length Lg of theantenna ground is at least twice a length Lp of patch antenna 116. Insome embodiments, the antenna ground has dimensions of about 2000μm×about 2000 μm. In some embodiments, a diameter of the antenna groundranges from about 2000 μm to about 3500 μm. If dimensions of the antennaground are too small, a strength of the signal conveyed from the activecircuit will be reduced, in some embodiments. If dimensions of theantenna ground are too large, the overall size of InFO antenna 100 isincreased without a significant increase in performance, in someembodiments.

Molding compound 114 is over RDL 112. Molding compound 114 is used tosecurely hold the active circuit to maintain connection with RDL 112. Insome embodiments, an adhesive layer is located between molding compound114 and RDL 112. In some embodiments, molding compound 114 has adielectric constant ranging from about 3.1 to about 4.0. In someembodiments, molding compound 114 includes a molding underfill, anepoxy, a resin or another suitable molding material. In someembodiments, molding compound 114 includes a curable material, such asan infrared-curable material, an ultraviolet-curable material, oranother suitable curable material.

Patch antenna 116 is above molding compound 114. Patch antenna 116 issubstantially centered above the antenna ground. Patch antenna 116includes a conductive material. In some embodiments, patch antenna 116includes a metal, a metal alloy or another suitable conductive material.In some embodiments, patch antenna 116 includes aluminum, copper,tungsten, nickel, combinations thereof or another suitable material.

Patch antenna 116 has a rectangular shape. In some embodiments, patchantenna 116 is circular, triangular or another suitable shape. In someembodiments, patch antenna 116 has a same shape as at least one ofreflector 104 or the antenna ground. In some embodiments, patch antenna116 has a different shape from at least one of reflector 104 or theantenna ground. Dimensions of patch antenna 116 are selected based on awavelength λ of the signal generated by the active circuity. In someembodiments, the wavelength λ of the signal ranges from about 4500 μm toabout 5500 μm. In some embodiments, a frequency of the signal rangesfrom about 55 gigahertz (GHz) to about 65 GHz, i.e., a bandwidth ofabout 10 GHz. In some embodiment, a center frequency of the signal isabout 60 GHz. A width Wp of patch antenna 116 ranges from about 1/10 λto about ½ λ. A length Lp of patch antenna 116 ranges from about 1/10 λto about ½ λ. In some embodiments, patch antenna 116 has dimensions ofabout 1000 μm×about 1000 μm. In some embodiments, a diameter of patchantenna 116 ranges from about 500 μm to about 2500 μm. If dimensions ofpatch antenna 116 are too small, the patch antenna 116 will notefficiently radiate the signal, in some embodiments. If dimensions ofpatch antenna 116 are too large, the overall size of InFO antenna 100 isincreased without a significant increase in performance, in someembodiments.

In comparison with some other approaches, InFO antenna 100 avoidscomplicated patterning to form a cavity within substrate 102. InFOantenna 100 includes reflector 104 smaller than the antenna ground. Thesize of reflector 104 provides a functioning device having a smallerarea in comparison with approaches which include solder balls outside aperimeter of a reflector. The structure of InFO antenna 100 also helpsto provide isolation between antenna elements to enhance array gain. Forexample, InFO antenna exhibits a gain of approximately 4 dBi. Incontrast, a device which includes solder balls outside the perimeter ofthe reflector exhibits a gain of approximately 1.5 dBi.

FIG. 1B is a bottom view of InFO antenna 100 in accordance with someembodiments. FIG. 1B includes the same elements as FIG. 1A. The antennaground formed by RDL 112 has width Wg and length Lg. In someembodiments, the antenna ground includes a diameter approximately equalto width Wg or length Lg. The dimensions of the antenna ground aregreater than the dimensions of reflector 104. Connecting elements 106are arranged over reflector 104 within the perimeter of the reflector104. The pitch P between connecting elements 106 helps to prevent thesignal reflected between reflector 104 and antenna ground from passingbetween adjacent connecting elements. Patch antenna 116 has dimensionsless than reflector 104. Patch antenna 116 has width Wp and length Lp.In some embodiments, patch antenna 116 includes a diameter approximatelyequal to width Wp or length Lp.

FIG. 2A is a cross-sectional view of an InFO antenna array 200 inaccordance with some embodiments. InFO antenna array 200 includessimilar elements as InFO antenna 100 (FIG. 1A). Similar elements have asame reference number increased by 100. InFO antenna array 200 includesa plurality of InFO antennas 200 a, e.g., InFO antenna 100. In someembodiments, the plurality of InFO antennas 200 a is arranged inrectangular pattern, e.g., 4×1; 2×2; 8×1; 4×2; 16×1; 8×2; 4×4; oranother suitable rectangular pattern. In some embodiments, the pluralityof InFO antennas 200 a is arranged in a circular, triangular or anothersuitable pattern. In some embodiments, the plurality of InFO antenna 200a is arranged in an irregular arrangement. In some embodiments, an arraypitch Pa between adjacent InFO antennas 200 a is greater than about ¼ λ.In some embodiments, the array pitch Pa ranges from about 1100 μm toabout 2200 μm. If the array pitch Pa is too small, one InFO antenna 200a may adversely impact operations of an adjacent InFO antenna, in someembodiments. If the array pitch Pa is too large, a size of InFO antennaarray 200 is increased without significant increase in performance, insome embodiments.

In some embodiments, dimensions of InFO antenna 200 a ranges from about10,000 μm to about 15,000 μm. In some embodiments, dimensions of InFOantenna 200 a are less than about 20,000 μm. If the dimensions of InFOantenna 200 a are too small, the InFO antenna will not efficientlytransmit the signal from the active circuit, in some embodiments. If thedimensions of InFO antenna 200 a are too large, a size of InFO antennaarray 200 is increased without significant increase in performance, insome embodiments.

In comparison with InFO antenna 100, InFO antenna array 200 includesactive circuit 250. Active circuit 250 is configured to generate thesignal transferred to RDL 212. Molding compound 214 helps to secureactive circuit 250 in place to maintain electrical connection with RDL212 for each InFO antenna 200 a, in some embodiments, active circuit 250is electrically connected to active elements in substrate 202. In someembodiments, active circuit 250 is electrically connected to passiveelements in substrate 202. In some embodiments, active circuit 250 isconfigured to generate the signal in response to a prompt from anexternal circuit. In some embodiments, active circuit 250 is configuredto generate the signal having a frequency ranging from about 55 GHz toabout 65 GHz. In some embodiments, dimensions of active circuit 250range from about 2000 μm to about 4000 μm. In some embodiments, InFOantenna array 200 exhibits a gain of approximately 14 dBi.

FIG. 2B is a perspective view of InFO antenna array 200 in accordancewith some embodiments. FIG. 2B includes a 4×4 array of InFO antennas 200a. In some embodiments, a number or arrangement of InFO antennas 200 ais different from the arrangement of FIG. 2B. Active circuit 250 islocated at a center point of the array of InFO antennas 200 a. In someembodiments, active circuit 250 is located at a position other than thecenter point of the array of InFO antennas 200 a.

FIG. 3 is a flowchart of a method 300 of making an integrated fan outantenna in accordance with some embodiments. In operation 302, areflector is formed on a surface of the substrate. The reflector, e.g.,reflector 104 (FIG. 1A), includes a reflective material. In someembodiments, the reflector includes a metal or metal alloy. In someembodiments, the reflector is formed by physical vapor deposition (PVD),chemical vapor deposition (CVD), sputtering, plating, or anothersuitable formation process. In some embodiments, the substrate, e.g.,substrate 102, is a PCB, an interposer, or another suitable substrate.

In operation 304, a redistribution layer (RDL), is formed in a package.The RDL, e.g., RDL 112 (FIG. 1A), is used to form an antenna ground inthe package, e.g., package 110. An area of the antenna ground is greaterthan an area of the reflector. The RDL is connected to an activecircuit, e.g., active circuit 250 (FIG. 2A), which is configured togenerate a signal. The RDL is configured to convey the signal from theactive circuit to the antenna ground. In some embodiments, the RDLincludes a metal or a metal alloy. In some embodiments, a material ofthe RDL is a same material as the reflector. In some embodiments, thematerial of the RDL is different from the material of the reflector. Insome embodiments, the RDL is formed by performing an etching process ona dielectric material to form openings within the dielectric material.The RDL is then formed within the openings in the dielectric material.In some embodiments, the RDL is formed within the openings in thedielectric material by PVD, CVD, sputtering, plating or another suitableformation process. In some embodiments, the RDL is formed using a sameprocess as the reflector. In some embodiments, the RDL is formed using adifferent process from the reflector.

A molding compound is formed over the RDL in operation 306. The moldingcompound, e.g., molding compound 114 (FIG. 1A), is used to secure thelocation of the active circuit. In some embodiments, the moldingcompound includes an underfill, an epoxy, a resin or another suitablematerial. In some embodiments, a dielectric constant of the moldingcompound ranges from about 3.1 to about 4.0. In some embodiments, themolding compound is formed by injection or another filling process. Insome embodiments, the molding compound is cured following introductionof the molding compound. In some embodiments, the molding compound iscured by infrared radiation, ultraviolet radiation, or other suitableradiation.

In operation 308, a patch antenna is formed over the molding compound.The patch antenna, e.g., patch antenna 116 (FIG. 1A), is configured totransmit the signal generated by the active circuit to externalcircuitry. An area of the patch antenna is less than an area of theantenna ground and the reflector. In some embodiments, the patch antennaincludes a metal or a metal alloy. In some embodiments, a material ofthe patch antenna is a same material as at least one of the reflector orthe RDL. In some embodiments, the material of the patch antenna isdifferent from the material of at least one of the reflector or the RDL.In some embodiments, the patch antenna is formed by performing anetching process on a dielectric material to form openings within thedielectric material. The patch antenna is then formed within theopenings in the dielectric material. In some embodiments, the patchantenna is formed within the openings in the dielectric material by PVD,CVD, sputtering, plating or another suitable formation process. In someembodiments, the patch antenna is formed using a same process as atleast one of the reflector or the RDL. In some embodiments, the patchantenna is formed using a different process from at least one of thereflector or the RDL.

In operation 310, the package is bonded to the substrate usingconnecting elements connected to the RDL and to a surface of thereflector. The connecting elements, e.g., connecting elements 106 (FIG.1A), are located within a perimeter of the reflector. The connectingelements are used to electrically and mechanically connect the packageto the substrate. In some embodiments, the connecting elements aresolder balls. In some embodiments, the connecting elements are copperpillars. In some embodiments, the connecting elements include at leastone UBM layer between the connecting elements and package. In someembodiments, the connecting elements are in direct contact with thereflector. In some embodiments, the connecting elements are separatedfrom the reflector by a portion of the substrate or at least one UBMlayer.

A diameter D of the connecting elements is selected to help create acavity between the antenna ground and the reflector. A pitch betweenadjacent connecting elements helps to prevent the signal from passingbetween the adjacent connecting elements. A number of the connectiveelements is determined by a size of the reflector, the diameter of theconnective elements, and the pitch between adjacent connective elements.

In some embodiments, the connective elements are formed by a screeningprocess, a printing process, a plating process, CVD, PVD, sputtering, oranother suitable formation process. In some embodiments, the connectiveelements are formed by a same process as at least one of the reflector,the RDL or the patch antenna. In some embodiments, the connectiveelements are formed by a different process from at least one of thereflector, the RDL, or the patch antenna. In some embodiments, thepackage is bonded to the substrate by a reflow process. In someembodiments, the package is bonded to the substrate by a eutecticbonding process.

In some embodiments, an order of operations of method 300 is altered.For example, the molding compound is formed prior to forming the RDL, insome embodiments. In some embodiments, additional operations are addedto method 300. For example, bonding the active circuit to the RDL isincluded in method 300, in some embodiments. In some embodiments, atleast operation of method 300 is omitted. For example, the moldingcompound is omitted, in some embodiments.

One aspect of this description relates to an integrated fan out (InFO)antenna. The InFO antenna includes a reflector on a surface of asubstrate; and a package. The package includes a redistribution layer(RDL) arranged to form an antenna ground, and a patch antenna over theRDL, wherein the RDL is between the patch antenna and the reflector. TheInFO antenna further includes a plurality of connecting elements bondingthe package to the reflector. Each connecting element of the pluralityof connecting elements is located inside an outer perimeter of thereflector. The InFO antenna is configured to output a signal having awavelength.

Another aspect of this description relates to an integrated fan out(InFO) antenna array. The InFO antenna array includes a substrate; andan active circuit configured to generate a signal having a wavelength.The active circuit is part of a package. The InFO antenna array furtherincludes a plurality of InFO antennas connected to the active circuit.Each InFO antenna of the plurality of InFO antennas includes a reflectoron a surface of the substrate; and a redistribution layer (RDL) arrangedto form an antenna ground in the package, wherein the RDL is connectedto the active circuit. Each InFO antenna of the plurality of InFOantennas further includes a patch antenna in the package over the RDL;and a plurality of connecting elements bonding the RDL to the reflector.Each connecting element of the plurality of connecting elements islocated inside an outer perimeter of the reflector.

Still another aspect of this description relates to a method of makingan integrated fan out (InFO) antenna. The method includes forming areflector on a surface of a substrate. The method further includesforming a redistribution layer (RDL) in a package, wherein forming theRDL comprises forming an antenna ground. The method further includesforming a patch antenna over the RDL, wherein the RDL is between thepatch antenna and the reflector. The method further includes bonding thepackage to the reflector using a plurality of connecting elements. Eachconnecting element of the plurality of connecting elements is locateddirectly above the reflector. The InFO antenna is configured to output asignal having a wavelength.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. An integrated fan out (InFO) antenna comprising:a reflector on a surface of a substrate; a package, the packagecomprising: a redistribution layer (RDL) arranged to form an antennaground, and a patch antenna over the RDL, wherein the RDL is between thepatch antenna and the reflector, an area of the entire antenna ground isgreater than an area of the entire reflector, and the RDL at leastpartially overlaps the patch antenna; and a plurality of connectingelements bonding the package to the reflector, wherein each connectingelement of the plurality of connecting elements is located inside anouter perimeter of the reflector, and the InFO antenna is configured tooutput a signal having a wavelength.
 2. The InFO antenna of claim 1,wherein at least one connecting element of the plurality of connectingelement is in direct contact with the reflector.
 3. The InFO antenna ofclaim 1, wherein the connecting elements are regularly arranged and apitch between adjacent connecting elements of the plurality ofconnecting elements blocks the signal from passing between the adjacentconnecting elements.
 4. The InFO antenna of claim 1, wherein an area ofthe reflector is greater than an area of the patch antenna.
 5. The InFOantenna of claim 1, wherein the connecting elements are regularlyarranged and a pitch between adjacent connecting elements of theplurality of connecting elements is greater than about 1.5 times adiameter of at least one connecting element of the plurality ofconnecting elements.
 6. The InFO antenna of claim 1, wherein a dimensionof the patch antenna ranges from about 1/10 λ, to about ½ λ, where λ isthe wavelength of the signal.
 7. The InFO antenna of claim 1, wherein adimension of the antenna ground is at least twice a dimension of thepatch antenna.
 8. The InFO antenna of claim 1, further comprising amolding compound between the RDL and the patch antenna.
 9. The InFOantenna of claim 1, wherein at least one connecting element of theplurality of connecting elements is electrically connected to the RDL.10. The InFO antenna of claim 1, wherein each connecting element of theplurality of connecting elements extends beyond an edge of the patchantenna in a top view.
 11. The InFO antenna of claim 1, wherein the RDLcomprises a feed structure for the InFO antenna, and the feed structurecomprises a transmission line and a slot line.
 12. An integrated fan out(InFO) antenna array comprising: a substrate; an active circuitconfigured to generate a signal having a wavelength, wherein the activecircuit is part of a package; and a plurality of InFO antennaselectrically connected to the active circuit, wherein each InFO antennaof the plurality of InFO antennas comprises: a reflector on a surface ofthe substrate; a redistribution layer (RDL) arranged to form an antennaground in the package, wherein the RDL is electrically connected to theactive circuit, a patch antenna in the package over the RDL, wherein theRDL at least partially overlaps the patch antenna, and a dimension ofthe antenna ground is at least twice a dimension of the patch antenna;and a plurality of connecting elements bonding the RDL to the reflector,wherein each connecting element of the plurality of connecting elementsis located inside an outer perimeter of the reflector.
 13. The InFOantenna array of claim 12, further comprising a molding compoundsurrounding the active circuit.
 14. The InFO antenna array of claim 12,wherein the plurality of InFO antennas is arranged in a regular pattern.15. The InFO antenna array of claim 12, wherein a pitch between adjacentconnecting elements of the plurality of connecting elements blocks thesignal from passing between the adjacent connecting elements.
 16. TheInFO antenna array of claim 12, wherein a pitch between adjacentconnecting elements of the plurality of connecting elements is greaterthan about 1.5 times a diameter of at least one connecting element ofthe plurality of connecting elements.
 17. The InFO antenna array ofclaim 12, wherein a dimension of the patch antenna ranges from about1/10 λ to about ½ λ, where λ is the wavelength of the signal.
 18. Amethod of making an integrated fan out (InFO) antenna, the methodcomprising: forming a reflector on a surface of a substrate, wherein thereflector is a continuous plate; forming a redistribution layer (RDL) ina package, wherein forming the RDL comprises forming an antenna ground,forming a patch antenna over the RDL, wherein the RDL is between thepatch antenna and the reflector, and the RDL at least partially overlapsthe patch antenna; and bonding the package to the reflector using aplurality of connecting elements, wherein each connecting element of theplurality of connecting elements is located above the reflector, and theInFO antenna is configured to output a signal having a wavelength. 19.The method of claim 18, wherein bonding the package to the reflectorcomprises using the plurality of connecting elements having a pitchbetween adjacent connecting elements of the plurality of connectingelements blocks the signal from passing between the adjacent connectingelements.
 20. The method of claim 18, wherein bonding the package to thereflector comprises using the plurality of connecting elements having apitch between adjacent connecting elements of the plurality ofconnecting elements greater than about 1.5 times a diameter of at leastone connecting element of the plurality of connecting elements.